Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a well that penetrates the hydrocarbon-bearing geologic formation. In subsea applications, the well is drilled at a subsea location and the flow of fluids may be handled by several different types of equipment. In subsea operations, for example, subsea equipment may comprise subsea completion systems which may include or work in cooperation with subsea installations mounted over a wellhead. The subsea installations may comprise various components, e.g. tubing hangers and subsea trees, and may incorporate fluid flow paths, e.g a production flow path and an annulus flow path. In a variety of traditional systems, an open plenum exists between a top of the tubing hanger and a bottom of the subsea tree. The annulus flow path effectively extends through the open plenum region but this can expose a variety of components to potentially deleterious well fluids or other fluids.